I can't comment on the life span of the optic fibres or the sharing of the bandwidth. The latter makes sense though. But the end of the email is pure BS. I know for a fact (I've seen it) that Telstra as already spent the money and the optic fibre infrastructure has been underground with any new development since 1995 so why would they possibly 'laugh and pick up the pieces'?
They're sitting tight and waiting for the pay-check to cash in IMO.